React Native state changes without me doing anything

I have this page where I give the details of a reservation and I need to allow users to change the date.

I created 2 properties in the state and loaded them with the same exact object gathered from the backend so that I can compare them later.

When the user changes the date only one of them gets updated with set state and the re-render triggers a function that checks if any changes are made.

dataDidChange(){        let reservationChanged = this.state.reservation.startAt === this.state.originalReservation.startAt && this.state.reservation.endAt === this.state.originalReservation.endAt;        console.log('DataChanged: ',reservationChanged);        return !(reservationChanged);    }

The problem is that apparently changing one changes the other too.

this.setState({                reservation: resp, // resp is the response from the backend                originalReservation: resp, // this state parameter isn't called anywhere else            });

I have 2 others state setting below but both of them only set reservation and not originalReservation, but both of them change anyway. How can I avoid this?

I tried with temporary variables before setting, I tried creating new Date objects with the same value, but nothing has worked.

let reservation = resp;let original = resp;original.startAt = new Date(original.startAt.getDate() + original.startAt.getTime());